A user may operate a machine, such as a user device, to request, receive, and present content (e.g., web content). For example, a user device may execute a browser application that, according to input from the user, requests a document (e.g., a webpage) from another machine, such as a server (e.g., webserver), which may respond by communicating the document to the user device. The user device may then present some or all of the document (e.g., some or all of the document's contents) within a window (e.g., graphical user interface window) on a display screen of the user device.